She runs an award-winning bed and breakfast in the Berkshire town, and was reported missing at 8am on Monday after vanishing from her sprawling country mansion.

Thames Valley Police are focusing their hunt on an area of nearby Windsor Great Park.

Mrs Brown's family described the mother-of-two as a "very special person" who was "loved and admired by everyone".

"This is a very difficult time for our family," they said in a statement. "We ask that anyone with any information about the whereabouts of Joanna contact the police."

The couple separated three years ago and were going through divorce proceedings. Their marital home - Tun Cottage, which borders Windsor Great Park - was converted into a guest house following their split. The mock-Tudor property - worth in the region of £3 million - is described on its website as "a beautiful English country home" and has been awarded a 4* Gold Award by Visit Britain.

Mrs Brown was understood to have lived at the mansion for 12 years before turning it into the upmarket guest house two years ago. She was from a privileged background and was described as fun and outgoing by a close friend. The couple married 11 years ago and had two children, an 11-year-old boy and a nine-year-old girl.

A police spokesman said a family member raised the alarm after he was unable to contact Mrs Brown on Monday. Officers forced their way into the house and a search led them to believe she had been attacked. No-one was inside at the time.

Mr Brown has been remanded in custody and will appear at Slough Magistrates' Court on Friday.